Field of the Invention
The present invention relates to a grid plate, a method of manufacturing the same, and an ion beam processing apparatus.
Description of the Related Art
Ion beam processing such as etching and ion implantation has widely been practiced in manufacturing processes of electronic components and the like. An ion beam processing apparatus used in this processing is often equipped with a thin plate (hereinafter referred to as a grid) including multiple holes used for extracting ions from plasma. This ion beam processing apparatus performs processing by irradiating a processing object with ions, which are originated from the plasma and transformed into beams as a consequence of passage through the holes in the grid.
Japanese Patent Application Laid-Open No. Hei 4-180621 describes a particle beam etching apparatus that includes grids. The particle beam etching apparatus uses the grids in a mesh form, each of which is formed either from layered films of carbon and silicon or from carbon fibers.
U.S. Pat. No. 5,548,953 describes a grid that uses a carbon-carbon composite as its material. The carbon-carbon composite in U.S. Pat. No. 5,548,953 has a structure in which some filaments of carbon fibers are bundled into strands that are then arranged in a woven fabric form and embedded into a carbon matrix (a base material) provided with multiple holes. As arrangement examples of the carbon fibers in the woven fabric form, U.S. Pat. No. 5,548,953 discloses the following examples in which: the carbon fibers are arranged parallel to three axes offset by 60° from one another (FIG. 7 of U.S. Pat. No. 5,548,953); the carbon fibers are snaked so as to skirt the holes (FIG. 8 of U.S. Pat. No. 5,548,953); and the carbon fibers are arranged in a lattice fashion (FIG. 9 of U.S. Pat. No. 5,548,953).